Spine-crowned Clubtail dragonfly (male)

May 8, 2017

A Spine-crowned Clubtail dragonfly (Hylogomphus abbreviatus) was spotted recently in Fairfax County, Virginia USA. Spine-crowned Clubtail is relatively uncommon in Northern Virginia, and a new species of dragonfly for my life list.

This individual is a male, as indicated by his terminal appendages and indented hind wings. Notice the right hind wing is slightly malformed.

Spine-crowned Clubtail versus Cobra Clubtail

Spined-crowned Clubtail looks similar to Cobra Clubtail (Gomphurus vastus). Two field markers can be used to differentiate the species.

Spine-crowned Clubtail features large yellow spots on the sides of abdominal segments eight and nine (S8-9); Cobra Clubtail has a small yellow spot on the side of abdominal segment eight (S8) and a large yellow spot on the side of abdominal segment nine (S9), as shown below (see inset photo).

03 MAY 2017 | Fairfax County, VA | Spine-crowned Clubtail (male)

(See a full-size version of the original photo, without annotation and inset photo.)

The face of Spine-crowned Clubtail is yellow and unmarked; the face of Cobra Clubtail is yellow with horizontal black markings (see inset photo).

03 MAY 2017 | Fairfax County, VA | Spine-crowned Clubtail (male)

(See a full-size version of the original photo, without inset photo.)

More photos, Spine-crowned Clubtail

This guy was a cooperative model as I followed him to several perches on rocks along a large stream.

03 MAY 2017 | Fairfax County, VA | Spine-crowned Clubtail (male)

03 MAY 2017 | Fairfax County, VA | Spine-crowned Clubtail (male)

03 MAY 2017 | Fairfax County, VA | Spine-crowned Clubtail (male)

03 MAY 2017 | Fairfax County, VA | Spine-crowned Clubtail (male)

Editor’s Notes: Special thanks to Mike Boatwright, curator of the Virginia Odonata Facebook group, for help in verifying my tentative field identification. As far as I know, this is the first official record for Hylogomphus abbreviatus in Fairfax County, Virginia.

Copyright © 2017 Walter Sanford. All rights reserved.

Springtime Darner dragonfly (male)

May 6, 2017

(✔︎) Springtime Darner dragonfly (Basiaeschna janata).

Well, now that I’ve seen a Springtime Darner, I can stop hunting for the species this year. Huh? I saw one Springtime Darner in 2015 (my first) and another one in 2016, both females. Apparently, Mother Nature allows me to see one and only one Springtime Darner per year. So check-off Springtime Darner from my target list of species for 2017 and move along, nothing more to see here folks. But seriously, hope springs eternal so I’ll keep looking for this somewhat elusive species.

03 MAY 2017 | Fairfax County, VA | Springtime Darner (male)

This Springtime Darner is a handsome male, as indicated by his terminal appendages and indented hind wings. (The former field marker is shown more clearly than the latter.) The blue coloration along its abdomen also indicates this individual is a male, although less reliably than other field markers since female Springtime Darners are polymorphic including blue and green morphs.

Look closely at the full-size version of the preceding photo — there’s some wild stuff going on in his eyes!

The Backstory

During the dragonfly-hunting “off season,” I had a hunch that a new location in Fairfax County, Virginia USA might be a good place to find some of the more uncommon species of odonates. On 03 May 2017, I visited the spot for the first time. I hiked in and began exploring a mid-size stream. After approximately 30-45 minutes of intensive searching, I hadn’t seen any dragonflies or damselflies and was thinking about moving on to another tried-and-true ode-hunting location.

Fortunately, I noticed something out of the corner of my eye that made me stop: a dragonfly that was perching near the ground made a quick, low flight to a new perch. I didn’t see the exact spot where it landed, but I had an idea of the area where it might be. Turns out it was a male Stream Cruiser dragonfly. The male Springtime Darner (featured in this post) was the next dragonfly I spotted soon afterward. Then it’s like the flood gates opened and I saw lots of other odonates including a new species of dragonfly for my life list.

So what’s the take-away from this experience? It’s a cliche, but persistence pays — don’t give up too soon! Oh, and follow your hunches, otherwise you’ll never know whether you are right. Speaking of hunches, I have a good hunch I’ll revisit the new site soon.

Snake in the grass

May 4, 2017

Continuing the “Reptiles of Riverbend Park” theme, here’s a photo of a Northern Watersnake (Nerodia sipedon sipedon) spotted near the same location as the Broad-headed Skink featured in my last blog post.

Gee, can you tell it was a slow day for odonates at Riverbend Park?

Copyright © 2017 Walter Sanford. All rights reserved.

Skink

May 2, 2017

A skink was spotted during a photowalk along the Potomac River at Riverbend Park, Fairfax County, Virginia USA. The lizard is either a Broad-headed Skink (Plestiodon laticeps) or an adult male Common Five-lined Skink (Plestiodon fasciatus).

This individual appears to have five (5) supralabial scales between the snout and the front of its eye, a field marker that indicates it’s probably a Broad-headed Skink.

Copyright © 2017 Walter Sanford. All rights reserved.

Voltinism, revisited

April 30, 2017

Voltinism is a term used in biology to indicate the number of broods or generations of an organism in a year. Source Credit: Wikipedia.

Some species of odonates, such as Southern Spreadwing damselfly (Lestes australis), can be multivoltine.

Huntley Meadows Park

Long-term monitoring of a vernal pool at Huntley Meadows Park has shown Southern Spreadwing is multivoltine at that site.

Mason Neck West Park

Males and females from a single brood of Southern Spreadwing were observed during Fall 2016 at Mason Neck West Park; males from another brood were spotted at the same location on 05 April 2017 and again on 18 April 2017. This evidence suggests Southern Spreadwing is multivoltine at Mason Neck West Park (MNWP). Further field observations are necessary to determine whether more than two broods occur at this location.

This individual is a male, as indicated by his coloration and terminal appendages.

Please look at the full-size versions of the preceding photos in order to appreciate the “fresh” coloration that seems to be a noticeable characteristic for many species of recently-emerged odonates.

Copyright © 2017 Walter Sanford. All rights reserved.

Ashy Clubtail dragonfly (male)

April 28, 2017

An Ashy Clubtail dragonfly (Phanogomphus lividus) was spotted during a photowalk at Riverbend Park, Fairfax County, Virginia USA. This individual is a male, as indicated by his indented hind wings and terminal appendages.

Male dragonflies have three terminal appendages, collectively called “claspers,” that are used to grab and hold female dragonflies during mating: an upper pair of cerci (“superior appendages”); and a lower unpaired epiproct (“inferior appendage”).

Notice the epiproct is a large “plate” that spans both cerci, as shown in the full-size version of the following photo.

One thing you can count on when photographing Ashy Clubtails (well, usually) is the subject will be perching on a chaotic background that is difficult to crop without creating leading lines that mislead the viewer’s eye and distracting elements near the edges of the image.

Copyright © 2017 Walter Sanford. All rights reserved.

Epitheca cynosura exuvia

April 26, 2017

On 13 April 2017, a late-stage emergent teneral female Common Baskettail dragonfly (Epitheca cynosura) was observed at Painted Turtle Pond during a photowalk around Occoquan Bay National Wildlife Refuge, Prince William County, Virginia USA.

Several dragonfly exuviae were collected near the same location as the emergent teneral female. All of the exuviae look identical, although there is some variation in size. A two-step process was used to verify the genus and species for one of the larger exuvia.

  • Determine the family.
  • Determine the genus and species.

This specimen is approximately 22 mm (~0.87 in) in length.

Step 1. Family

First, determine the family of the specimen. For reference, watch the excellent Vimeo video, Identifying dragonfly larva to family (8:06). Here’s the decision tree used to identify the exuvia as a member of the Family Corduliidae (Emeralds).

  • The specimen has a mask-like labium that covers the face, characteristic of four families: Cordulegastridae (Spiketails); Corduliidae (Emeralds); Libellulidae (Skimmers); and Macromiidae (Cruisers).
  • There is no horn on top of the face-head, characteristic of Macromiidae, so it’s not a cruiser.
  • Cordulegastridae has jagged crenulations on its labium, so it’s not a spiketail. The crenulations for Corduliidae and Libellulidae look similar.
  • Look at the anal pyramid to differentiate Corduliidae and Libellulidae [See Photo No. 7.]: It’s probably Corduliidae if the cerci are at least half as long as the paraprocts. [Editor’s Note: It’s probably Libellulidae if the cerci are less than half the length of the paraprocts.]

In summary, the exuvia has a mask-like labium with relatively smooth crenulations, no horn on its face-head, and the cerci are more than half as long as the paraprocts, confirming that the specimen is a member of Family Corduliidae (Emeralds).

(See a full-size version of the original photo, without annotation.)

Notice that dorsal hooks are present and well developed on most abdominal segments.

No. 4 | Common Baskettail (Epitheca cynosura) | exuvia (dorso-lateral)

A lateral view of the exuvia provides a good look at the labium, also known as the mentum, a two-segment hinged “jaw” that is used to grab food: the prementum is the segment of the labium closer to the mouth; the postmentum is the segment closer to the base of the head.

The white filaments that extend from the split in the thorax (as shown in Photo No. 1-7) are breathing tubes, artifacts of the unique respiratory system of dragonfly nymphs.

(See a full-size version of the original photo, without annotation.)

A closer view of the head shows two “bumps” that may be a pair of tubercles.

Step 2. Genus and species

Characters from Identification Keys to Northeastern Anisoptera Larvae, dichotomous keys compiled by Ken Soltesz, were used to identify the genus and species for the exuvia. Although palpal/mental setae were not examined, all other characters match Epitheca cynosura.

dichotomous key: a key for the identification of organisms based on a series of choices between alternative characters. Source Credit: Merriam-Webster Dictionary.

Alternate Key to the Genera of the Family Corduliidae, p. 29.

Key to the species of the genus (subgenus) Tetragoneuria, p. 32.

No. 7 | Common Baskettail (Epitheca cynosura) | exuvia (anal pyramid)

(See a full-size version of the original photo, without annotation.)

The last photo shows a ventral view of the exuvia. The vestigial hamuli located between abdominal segments two and three (S2-3) strongly suggests this individual is a male, therefore this specimen probably is not the same exuvia from which the teneral female emerged.

(See a full-size version of the original photo, without annotation.)

Tech Tips:

The following equipment was used to shoot all of the preceding photographs: Canon EOS 5D Mark II digital camera, in manual mode; Canon EF100mm f/2.8L Macro lens (set for manual focus) plus a Kenko 20mm macro automatic extension tube; Canon 580EX II external flash tethered to the camera by a coiled six-foot Vello Off-Camera TTL Flash Cord for Canon Cameras, off-camera, in manual mode; the Canon flash optically triggered a small Nissin i40 external flash (in SF mode) used for backlight; and a Sunpak LED-160 Video Light with a white translucent plastic filter used for side light.

Adobe Photoshop CC 2017 was used to annotate selected images.

Related Resources:

Editor’s Note: Sincere thanks to Sue Gregoire, Kestrel Haven Migration Observatory, for verifying my tentative identification, and for sharing some good odonate nymph knowledge regarding vestigial hamuli!

Copyright © 2017 Walter Sanford. All rights reserved.

Blue Corporal dragonflies (males)

April 24, 2017

Several Blue Corporal dragonflies (Ladona deplanata) were spotted at Hidden Pond, Meadowood Recreation Area, Fairfax County, Virginia USA. All of the individuals featured in this post are males, as indicated by their coloration and terminal appendages.

Blue Corporals are among the first species of odonates to emerge in the spring, beginning in mid-April. Hidden Pond is one of a few places in Northern Virginia where Blue Corporals are relatively common.

Although Blue Corporals prefer to perch flat on the ground, sometimes they pose for “Odonarty” photos, as shown below.

Copyright © 2017 Walter Sanford. All rights reserved.

Non-stop flight

April 22, 2017

On 18 April 2017, a Common Baskettail dragonfly (Epitheca cynosura) was spotted patrolling part of the shoreline at Mulligan Pond, Jackson Miles Abbott Wetland Refuge, Fairfax County, Virginia USA. This individual is a male, in flight.

108mm (600mm equivalent) | ISO 100 | f/5.2 | 1/800s | -1 ev | flash fired

The photograph was taken using a Panasonic LUMIX DMC-FZ150 superzoom bridge camera and a Canon 580EX Speedlite external flash set for manual mode at 1/8 power and 105mm zoom.

Related Resource: Stop-action photography of dragonflies in flight, a blog post by Walter Sanford, features Phil Wherry’s answer to my question “How fast would the camera shutter speed need to be in order to freeze all motion of a dragonfly in flight?”

Copyright © 2017 Walter Sanford. All rights reserved.

Phanogomphus

April 20, 2017

Two teneral dragonflies were observed near Mulligan Pond during a photowalk at Jackson Miles Abbott Wetland Refuge, Fairfax County, Virginia USA. I was able to photograph the first one I spotted; the second flew away as soon as I approached it.

This dragonfly is either Ashy Clubtail (Phanogomphus lividus) or Lancet Clubtail (Phanogomphus exilis). Based upon the short, faded yellow markings on the dorsal side of abdominal segments eight and nine (S8-9), this individual is probably an Ashy Clubtail dragonfly. Less reliably, the 18 April date of the spotting also suggests Ashy Clubtail (for Northern Virginia).

18 APR 2017 | JMAWR | Ashy Clubtail or Lancet Clubtail (female)

Both Ashy- and Lancet Clubtail dragonflies were formerly classified as members of the genus Gomphus. Both species were reclassified recently as Phanogomphus. In the world of taxonomic classification, there are “lumpers” and “splitters.” Score one for the splitters!

Notice the first photo shows the wings folded above the abdomen. I spotted the teneral dragonfly when it flew toward me from the pond shoreline. The dragonfly rested in this location for a few minutes before it flew to a new spot (shown below) where it perched briefly with its wings unfolded. The last time I saw the dragonfly, it was flying toward the forest alongside the pond.

The other teneral dragonfly that I saw — “the one that got away” — was perched on the lawn near the walking path around the lake; it flew toward the forest when I moved closer to take some photographs.

18 APR 2017 | JMAWR | Ashy Clubtail or Lancet Clubtail (female)

(See a full-size version of the original photo, without annotation.)

This specimen is a female, as indicated by her rounded hind wings and terminal appendages.

All female dragonflies have two cerci (superior appendages); in contrast all male dragonflies have two cerci and one epiproct (inferior appendage), collectively called “claspers.” Contrast the appearance of the terminal appendages of this female Ashy Clubtail with a male of the same species.

The last photo in the set is a wider view that shows how well-camouflaged the dragonfly was perched on the lawn around the pond.

18 APR 2017 | JMAWR | Ashy Clubtail or Lancet Clubtail (female)

The Backstory

I was surprised to discover a Lancet Clubtail dragonfly near Mulligan Pond during late-June 2016. Knowing that Ashy Clubtails can be found in the same habitats preferred by Lancet Clubtails, I decided to look for Ashy Clubtails at Jackson Miles Abbott Wetland Refuge beginning in mid-April 2017. Apparently Mulligan Pond is a good place for both species, because I spotted two Ashy Clubtails the first time I went looking for them. Ah, if only odonate hunting were always so easy!

Post Update

As far as I know, this is the first record for this species at this location. A new record for Ashy Clubtail (Phanogomphus lividus) at Jackson Miles Abbott Wetland Refuge was submitted to the Odonata Central records database on 22 April 2017.

Copyright © 2017 Walter Sanford. All rights reserved.


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